Passenger arm rest assemblies may be mounted on a back seat of a motorcycle. Generally, arm rest assemblies are coupled to a frame of the passenger seat and extend outward toward a front of the motorcycle. The arm rest may be designed to rotate about an axis to provide comfort to the passenger. Additionally, the arm rest may be designed to raise or lower vertically to provide additional comfort to the passenger. Typically, the arm rest should be secured in such a manner as to prevent unwanted rotation or vertical movement; as such movement may be dangerous, particularly when the motorcycle is in operation.